Many kinds of removable band-type clamps or couplings (referred to herein as clamps, and the terms being used interchangeably) for pipes exist in the art. It is noted that throughout the specification and claims, the term “pipe” encompasses any kind of generally cylindrical object.
Couplings for connecting pipes of the same or different diameters are known, an example of which is shown in FIG. 1. A clamp or coupling 1 has a ring shaped seal 2 made of rubber or other resilient material, which may be constructed of a first ring seal seated over a second ring seal. The seals can be easily disconnecting from one another to allow sealing against different diameter pipes. For smaller diameter pipes, both the first and second ring seals are used; for larger diameters, only one seal is used. FIG. 1 shows coupling 1 clamped against two pipes 3 and 4.
The clamp 1 typically includes a circumferentially continuous band 5 that has two ends separated by a gap. Typically, clamping members 6 are secured to the ends of band 5. One or more tightening fasteners 7 are used to tighten the two clamping members 6 to each other and effect the seal on the pipe.
It is known to use a spanning element, known as a bridge or clamp bridge 8, in such couplings, shown in FIG. 2. The bridge 8 spans the abovementioned gap located at the tightening mechanism. The bridge helps keep the sealing rings in place when tightening the clamp.
A problem, however, can occur with prior art bridges, which are made of a single piece of metal, typically stainless steel. If two pipes of different diameters are used, as seen in FIG. 3, one end 8A of the bridge 8 is tightened against a different diameter than the other end 8B of the bridge 8. The causes the bridge 8 to distort and can cause the bridge 8 to dig in and damage the seal 2 and/or part of the coupling body.